Direct casting of channel-shaped strip

ABSTRACT

Strip of channel-like cross section is continuously cast from molten metal on the inside surface of an upright chill ring rotating about its horizontal axis, at each end of which contiguous flanges project inwardly inclined to the ring surface at an angle of more than 90* . In some embodiments, the apparatus is adapted to cast channel-shaped strip with fluted flanges.

United States Patent [1 1 Gerding [4 1 Nov. 20, 1973 1 DIRECT CASTING OF CHANNEL-SHAPED STRIP [76] Inventor: Charles Christian Gerding, 728 Gaywood Dr., Pittsburgh, Pa. 15235 [22] Filed: Nov. 9, 1971 [21] Appl. No.: 197,090

Related U.S. Application Data [63] Continuation-in-part of Ser. No. 119,143, Feb. 26,

1971, abandoned.

[52] U.S. Cl. 164/276, 164/283 MS [51] Int. Cl B2211 11/06 [58] Field of Search 164/87, 88, 276, 164/277, 283 MS [56] References Cited UNITED STATES PATENTS 2,034,692 3/1936 Breitbait 164/300 2,383,310 8/1945 Hazelett 164/277 X 2,450,428 10/1948 Hazelett 164/277 2,663,921 12/1953 Cito 164/118 X 2,962,777 12/1960 Harrison 164/70 3,538,978 11/1970 Boehm 164/87 3,627,025 12/1971 Tromel et a1. 164/87 X 3,279,000 10/1966 Cofer et a1 164/87 X FOREIGN PATENTS OR APPLICATIONS 661,073 11/1951 Great Britain 164/84 1,177,758 1/1970 Great Britain 164/87 Primary Examiner-R. Spencer Annear Att0rneyG. R. Harris et a1.

[57 ABSTRACT Strip of channel-like cross section is continuously cast from molten metal on the inside surface of an upright chill ring rotating about its horizontal axis, at each end of which contiguous flanges project inwardly inclined to the ring surface at an angle of more than 90. In some embodiments, the apparatus is adapted to cast channel-shaped strip with fluted flanges.

11 Claims, 4 Drawing Figures PATENTEUNUWO m3 SHEET 2 BF 2 .NVENTOR.

CHARLES C. GERDING BY I fivis ATTORNEY DIRECT CASTING OF CHANNEL-SHAPED STRIP This application is a continuation-in-part of my application Ser. No. 119,143, filed Feb. 26, 1971 now abandoned.

This invention relates to the direct casting of strip from molten metal. It is more particularly concerned with apparatus and method for casting strip of channelshaped cross section on the inside surface of an upright rotating ring.

Apparatus for continuously solidifying molten metal into flat strip on the inside surface of a chill ring is described, among other matters, in U. S. Pat. No. 2,383,310 granted to C. W. I-Iazelett on Aug. 21, 1945. In spite of the various advantages of the apparatus of the Hazelett patent, it has remained neglected for 25 years. It is probable that this neglect was occasioned by the freezing of unwanted fins on the edges of the casting. Although I-Iazelett attempted to eliminate freezing on his vertical edge dams by insulating them with bone black, it is found extremely difficult in practice to prevent solidification on any such insulating surface when it is in intimate proximity to a chill surface. Also, the insulating layer so provided is difficult to maintain.

US. Pat. No. 2,450,428 also granted to C. W. Hazelett on Oct. 5, 1948 discloses apparatus which he says overcomes the disadvantages of the apparatus of his earlier patent hereinbefore mentioned. The apparatus of the later patent casts channel-shaped strip either on the inside or the outside surface of a roll or a ring or on the outside surface of a band. The problem then becomes what to do with the cast strip leaving the casting apparatus. It cannot be conveniently coiled because of its channel cross section and if the flanges are of any significant depth, the strip can be flattened only with extreme care. Because the strip solidifies in an arc of the circle the metal at the edge of the flanges is worked severely in flattening and is easily cracked.

I have invented improved apparatus for continuously solidifying molten metal on the inside surface of a rotating ring as channel-shaped strip which avoids the problems of the prior art. My apparatus casts channelshaped strip the flanges of which are fluted so as to provide extra metal at the edges of the flanges. When the channel-shaped strip is flattened, the presence of this extra metal allows the flanges to be straightened out without cracking.

Embodiments of my invention presently preferredby me are illustrated in the attached figures to which reference is now made.

FIG. 1 is a side elevation of apparatus of my invention.

FIG. 2 is a cross-section of the apparatus of FIG. 1 taken on the plane 22 thereof.

FIG. 3 is a partial perspective, broken away in part, of another embodiment of my invention.

FIG. 4 is a partial perspective broken away in part, of still another embodiment of my invention.

My apparatus as illustrated in FIGS. 1 and 2 comprises a cylindrical ring provided with integral circular outwardly extending radial flanges ll-l1 at its ends. Ring 10 is mounted upright for rotation about its axis on rolls l2 and 13 which, in turn, are mounted on pedestals l4 and 15, respectively, at the same height. The shaft 21 on which roll 13 turns is provided with an outboard pulley 16. On a pedestal 17 spaced from pedestal is mounted a drive motor 18 having a drive pulley 19 which is aligned with pulley 16. Around these pulleys is trained a driving belt 20.

The central portion 23 of the inside surface of ring 10 is cylindrical. At each open end of ring 10 this central portion merges into a flange portion 24 which is inclined axially outwardly and toward the axis of ring 10 at an angle greater than for example, about Surface 23 and flanges 24 thus form a channel extending around the inside of ring 10.

Pivotally mounted on an extended end of shaft 21 is an arm 29. The bore of arm 29 through which shaft 21 passes is provided with anti-friction bearings so that shaft 21 can turn freely and so that arm 29 can pivot through a small angle upon shaft 21. At its other end arm 29 journals a rotatable shaft 28 which is positioned parallel to shaft 21. The end of shaft 28 adjacent ring 10 carries a roll 25 which has a cylindrical outside surface portion 26 of somewhat lesser width than the cylindrical inside surface 23 of ring 10. Each end 27 of roll 25 is beveled at essentially the same angle as flange 24 of ring 10, the width of each bevel being essentially the same as that of flange 24. Roll 25 is hollow, as is shaft 28. At the end of shaft 28 remote from ring 10 is affixed a bevel gear 30 which mates with a second bevel gear 31 carried by counter shaft 32 which is joumaled on arm 29 with its axis parallel to the long axis of arm 29. The other end of counter shaft 32 is provided with a third bevel gear 33 which mates with a fourth bevel gear 34 affixed to the end of shaft 21. At the end of arm 29 adjacent shaft 28 is pivotally attached a hanger rod 36 carrying at its lower end a weight 37. Hanger rod 36 passes through a hole in horizontal upper end 45 of stationary bracket 47. Hanger rod 36 is threaded, as shown, and is provided with an adjustable nut 52 positioned above bracket end 45 and a second adjustable nut 53 positioned below bracket end 45.

A conduit for cooling fluid 38 extends through hollow shaft 28 into the interior of roll 25. The cooling fluid so introduced returns through the annular space between the interior surface of hollow shaft 28 and the exterior surface of conduit 38 and is discharged at the outer end of shaft 28 through outlet 39. Cooling fluid conduit 38 is connected to a source of cooling fluid not shown, and cooling fluid outlet 39 discharges into a sump, not shown. Around the circumference of ring 10 above rolls 12. and 13 is positioned an arcuate fluid header 40 which is spaced from the outer surface of ring 10. Cooling fluid is introduced into header 40 from a source not shown through inlet pipe 41. I-Ieader 40 is provided with a plurality of spray nozzles 42 spaced around the circumference of ring 10. Around the bottom surface of ring 10 between rolls l2 and 13 is positioned a second cooling fluid header 43 which is likewise connected to a source of cooling fluid, not shown, through inlet 44. Header 43 is likewise provided with spray nozzles 42. The spray nozzles 42 are formed so that the spray cone of cooling fluid emitted therefrom is contained within the end flanges 11-11 of ring 10, as is shown by dotted lines 46 in FIG. 2.

Outside ring 10 and positioned above the upper end of arm 29 is a launder or tundish 48 provided with a nozzle 49 directed to discharge molten metal into the interior of ring 10. In one embodiment of my invention, arm 29 is dimensioned to position roll 25 at some displacement angle from the lowest level of flange 24 of ring 10, as roll 25 is shown in solid lines of FIG. 1. In another embodiment of my invention arm 23 is dimensioned to position roll 25 at the lowest level of surface 23, as roll 25 is shown in dotted lines 25 of the same figure. Roll 25 is spaced from nozzle 49 in the direction of rotation of ring 10, which is shown in FIG. 1 as being counter-clockwise. Spaced beyond roll 25 in the same sense in scraper 59 having a sharp lower edge 51 bearing against the inside surface 23 of the ring ill.

The operation of my apparatus will be described in the terms of the foregoing description thereof. In one embodiment of my apparatus roll 25 is not employed and is therefore removed from ring or positioned out of contact therewith. Motor 18 is started, driving roll 13. The rotation of roll 13 causes ring 10 to rotate in the counter-clockwise direction shown in FIG. 1. Molten metal to be cast is teemed into tundish 48 and is delivered through noule 49 to the inside of ring 10. The molten metal forms a molten pool which is contained by the channel formed by the lowest region of inside cylindrical surface 23 and the inside flanges 24 of ring 10. This pool is wider transversely of that channel at its upper surface than at its bottom. Cooling fluid, normally water, is sprayed onto the outer surface of ring 10 through spray nozzles 42. The molten metal in the pool is chilled at its interface with ring it and the rotation of ring 10 carries channel-shaped solidified metal strip up and outwardly from the pool of molten metal toward scraper 50. This scraper is positioned far enough from the lowest point of ring surface 23, and the speed of rotation of ring 10 is so adjusted, that the cast strip has solidified before it encounters scraper 50. The pertinent structure is illustrated in FIG. 3. Roll 55, corresponding to roll 25 of FIGS. 1 and 2, has its beveled ends formed of alternate convex radial flutes or corrugations 56 and concave flutes or corrugations 57. These flutes taper in depth from a maximum around the ends of the roll to a minimum around the full circumference of the body of the roll. Flange 58 corresponding to flange 24 of FIGS. 1 and 2 is formed of alternate convex inward radial flutes 59 and concave inward radial flutes 60. These flutes likewise taper in depth from a maximum around the outside circumference of the flange to a minimum around the inside circumference of the flange. Convex flutes 56 of roll 55 mate with concave flutes 60 of flange 58 and concave flutes 57 of roll 55 mate with convex flutes 59 of flange 58. The flanges of the channel-shaped strip cast between roll 55 and ring 10 are fluted so that the overall length of the top edge of the cast flange is greater than that of a smooth flanged channel cast to the same radius and other dimensions. The depth of the flutes is adjusted so that the overall length of the top edge of the flange is equal to or greater than the length of the bottom edge. Thus, when arcuate cast channel-shaped half strip from the roll is continuously welded to the half strip cast in the ring, the flutes supply the extra metal needed by the edges of the roll cast channel which become the inside of the edges of a more nearly flattened strip. My apparatus may be constructed with a smoothly beveled roll 25 and a fluted flange 58, or with a fluted beveled roll 55 and a smooth flange 24 as operations may require.

Although it is desirable to position roll 25 at the lowest level of inner face 23 of ring 10, roll 25 may be positioned somewhat above the lowest level, at a level intermediate the lowest level and the highest level of the molten metal in the pool. it should, however, be positioned low enough that its beveled ends 27 chill the inner surface of the metal which solidifies against flanges 24 of ring 10.

Still another embodiment of my invention is illustrated in FIG. 4. In this embodiment rotating ring 62, otherwise identical with ring 10 in the embodiments previously described, is formed with a cylindrical inside surface 63 and outwardly extending radial flanges l l at each end, but with no integral axially outwardly and radially inwardly extending flanges, Stationary axially outwardly and radially inwardly extending flanges 64 are positioned at each end of ring 62 at the bottom thereof so as to form with the moving ring a channelshaped receptacle for molten metal. Each flange 64 has a surface 65 which is inclined toward the axis of ring 62 at an angle greater than with surface 63, for example, about The lower edge 66 of each surface 65 is arcuate, of the same radius as the ring 62, and marks the junction of inclined surface 65 with a vertical surface 67. The flanges 64 are positioned with respect to ring 62 so that each surface 67 is contiguous to an edge 68 of ring 62. By contiguous I mean that the contact between surface 67 and edge 68 is close enough to prevent molten metal from running down between them. Spray nozzles '70 are positioned to direct cooling fluid against the outside face of surface 65 and spray nozzles 42 are positioned, as before, to direct cooling fluid against the outside surface of ring 62. Flanges 64 chill the molten metal in contact therewith in the same way as do flanges 24 in the other embodiments of my invention previously described.

Mounted for rotation within ring 62 is roll 25, in the manner previously described. Where surfaces 65 are dimensioned to produce a high-sided channel casting and where the diameter or roll 25 is relatively small compared to that of ring 62, a fluted beveled end roll 55 as has been previously described and illustrated in FIG. 3 is substituted therefor.

The operation of the embodiment of my invention next above described differs from that of the other embodiments described herein only in that the flanges of the cast channel section of the strip solidify against chill surfaces 65 which are not moving with the strip but which are stationary with respect thereto, Strip is cast with or without roll 25 as requirements dictate, and when roll 25 or fluted end roll 55 is used, it is posi tioned at the lowermost level of the inner surface of ring 62 or at some level thereabove as requirements dictate, in the manner previously described.

The ratio of the gears in the train 31, 32, 33 and 34 is adjusted so that the linear speed of surface 26 of roll 25 is the same of that of the upper surface of the solidifying strip. As the linear speed of the upper surface of the solidified strip changes with changes in the thickness of the strip, it is desirable to change one or more of the gears in the train when a substantial change in strip thickness is to be effected. For a given ring it) and roll 25 the greatest flexibility of operation results when the angle of inclination of flanges 24 and bevels 27 is about 135 or more. It will be evident that if the angle were 90, the thickness of the flanges of the cast strip would always be the same regardless of the thickness of the web portion of the strip.

Ring 1!) is rotated at a circumferential speed adjusted to the rate of pour of molten metal through nozzle 49 so that the strip is solidified before it makes contact with scraper 50. I find that acceptable steel strip of about 1/4 inch thickness can be solidified in my apparatus at a lineal speed of about 30 feet per minute.

I claim:

1. Apparatus for continuously casting metal strip comprising a rigid ring having a cylindrical chill wall, means for supporting the ring with its axis horizontal for rotation thereabout, flange chill means contiguous to at least the lower most portion of the cylindrical chill wall at each edge thereof extending axially outwardly and radially inwardly therefrom so as to form therewith a channel-shaped chill surface with its flanges inclined to the chill wall at an angle of more than 90, means for delivering molten metal onto the channel-shaped chill surface, and means for applying cooling fluid to the outside surface of the ring and to the outside surfaces of the flange chill means at least in a location where said surfaces contact the molten metal so that the mo]- ten metal solidifies thereagainst as a strip of channelshaped cross section.

2. The apparatus of claim 1 including radially outwardly extending flanges at each end of the ring, and in which the means for supporting the ring for rotation comprise rolls on which the outwardly extending flanges rest.

3. The apparatus of claim 2 in which the means for supplying cooling fluid to the outside surface of the ring are adjusted to supply it between the radially outwardly projecting flanges, and extend around the top of the ring.

4. The apparatus of claim 1 in which the flange chill means are integral with the rigid ring and are inwardly fluted, the flutes tapering in depth from a maximum around the inside circumference of the flange chill the ring in its lower portion, the chill roll ends being beveled so that the roll mates with the channel-shaped chill surface, and means for supplying cooling fluid to the inside of the chill roll.

6. The apparatus of claim 5 in which the chill roll is positioned to mate with the channel-shaped chill surface at a level above the lowest level of the edges of the flange chill means so that the chill roll does not chill the molten metal delivered onto the channel-shaped chill surface.

7. The apparatus of claim 5 in which the chill roll is positioned to mate with the channel-shaped chill surface at a level below the lowest level of the edges of the flange chill means so that the chill roll chills the molten metal delivered onto the channel-shaped chill surface.

8. The apparatus of claim 5 including means for adjusting the pressure exerted by the hollow chill roll.

9. The apparatus of claim 5 including means for adjusting the gap between the hollow chill roll and the ring.

10. The apparatus of claim 5 in which the chill roll beveled ends are fluted, the flutes tapering in depth from a maximum around the ends of the roll to a minimum around the circumference of the roll body.

11. The apparatus of claim 10 in which the flange chill means are integral with the rigid ring, the flange chill means are fluted, and the flutes of flange and roll end mate.

Umrnn STATES rArnNr @FFIQE CERTEEIATE @Qh ECTEN iPatent No. 3, 773,102 Dated November 20, 1973 inventor) Charles Christian Gcrding It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Column 3, between Line 30 and Line 33., the following paragraphs .f should be inserted:

--The sharp edge 51 lifts the strip from the inside surface of ring 2 l0 and the solidified. strip is removed from my apparatus by spiralling it out through an open end of ring 10. find that a preferred method of spiralling involves a spiral angle of almost 360 so that the channel-shaped strip exists an an essentially horizontal plane near the molten pool contained in the casting ring.

In another embodiment of my invention roll 25 is employed. in the position in which it is shown in Figure 1.. In this position, its outer T surface 26 makes contact with the inner surface 23 of ring 10, in the absence of metal, at a level above the highest level of the molten metal in the pool previously mentioned. Normally, this level is above the 1 lowest level of the edges of flanges 2 As the solidified strip is 5 movedaway from the pool of molten metal by rotation of ring 10, roll 25 contacts the upper surface of the solidifying strip and facilitates i cooling and solidification thereof. When roll 25 is used in this way,

scraper 50 can be spaced closely thereto as the pressure exerted by roll 25 prevents the lifting effect of scraper 50 from disrupting the partially solidified strip on the other side of roll 25. D1 a third embodiment of my invention, roll 25 is positioned as shown by dotted lines 25' in Figure l at the lowermost level of inner surface 23 of ring 10. This level is below the lowest level of the edges of flanges 2 In this mode of operation, the molten metal in g the pool is chilled from both sides as it starts to solidify, The

thickness of the solidifying strip is controlled. by adjusting the gap between roll 25 and ring 10. This adjustment is made by rotating nuts FORM PC3-1050 (10-69) uscoMM-Dc eoa're-poo I U.S, GOVERNMENT PRINTING OFFICE: 1969 0-356-334,

PME 2 fPatent No. 3,773,102 Dated November 20 1973,

Inventor(s) Charles Christian Gerding I It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

- Continued.

52 and 53 on hanger rod 36 so as to move them upwardly or downwardly as required. Roll 25 is locked in its desired position by tightening 1 nuts 52 and. 53 gainst bracket end +5. Alternatively, nuts 52 and.

" 53 are rotated to move them away from bracket end +5, and the strip 4 thickness is controlled by the gravitational pull of weight 37. Either nut 52 or nut 53 can be useu by itself to set minimum or maximum strip thickness, respectively.

- To enhance the two-sides casting of channel with high sides, and

particularly when the roll 25 is small compared. to the ring 10, the

' mating bevel surfaces of my inner roll are formed as radially fluted,

surfaces.--

Signed and sealed this 8th day of October 1974.

I (SEAL) Attest:

5 McCOY M. GIBSON JR. 6. MARSHALL DANN Attesting Officer Commissioner of Patents FORM pomso UscoMM-oc 60376-P69 9 [L5, GOVERNMENT PRINTING OFFICE 7 IBIQ D355'33. 

1. Apparatus for continuously casting metal strip comprising a rigid ring having a cylindrical chill wall, means for supporting the ring with its axis horizontal for rotation thereabout, flange chill means contiguous to at least the lower most portion of the cylindrical chill wall at each edge thereof extending axially outwardly and radially inwardly therefrom so as to form therewith a channel-shaped chill surface with its flanges inclined to the chill wall at an angle of more than 90*, means for delivering molten metal onto the chanNel-shaped chill surface, and means for applying cooling fluid to the outside surface of the ring and to the outside surfaces of the flange chill means at least in a location where said surfaces contact the molten metal so that the molten metal solidifies thereagainst as a strip of channel-shaped cross section.
 2. The apparatus of claim 1 including radially outwardly extending flanges at each end of the ring, and in which the means for supporting the ring for rotation comprise rolls on which the outwardly extending flanges rest.
 3. The apparatus of claim 2 in which the means for supplying cooling fluid to the outside surface of the ring are adjusted to supply it between the radially outwardly projecting flanges, and extend around the top of the ring.
 4. The apparatus of claim 1 in which the flange chill means are integral with the rigid ring and are inwardly fluted, the flutes tapering in depth from a maximum around the inside circumference of the flange chill means to a minimum around the outside circumference of the flange chill means.
 5. The apparatus of claim 1 including a hollow chill roll mounted for rotation about a horizontal axis within the ring in its lower portion, the chill roll ends being beveled so that the roll mates with the channel-shaped chill surface, and means for supplying cooling fluid to the inside of the chill roll.
 6. The apparatus of claim 5 in which the chill roll is positioned to mate with the channel-shaped chill surface at a level above the lowest level of the edges of the flange chill means so that the chill roll does not chill the molten metal delivered onto the channel-shaped chill surface.
 7. The apparatus of claim 5 in which the chill roll is positioned to mate with the channel-shaped chill surface at a level below the lowest level of the edges of the flange chill means so that the chill roll chills the molten metal delivered onto the channel-shaped chill surface.
 8. The apparatus of claim 5 including means for adjusting the pressure exerted by the hollow chill roll.
 9. The apparatus of claim 5 including means for adjusting the gap between the hollow chill roll and the ring.
 10. The apparatus of claim 5 in which the chill roll beveled ends are fluted, the flutes tapering in depth from a maximum around the ends of the roll to a minimum around the circumference of the roll body.
 11. The apparatus of claim 10 in which the flange chill means are integral with the rigid ring, the flange chill means are fluted, and the flutes of flange and roll end mate. 